In spite of federal and state water quality regulations, the quality of water provided by municipalities, public wells, and the like to consumers, such as domestic households, ranges widely. Households in fact are still susceptible to contaminants in drinking water. Lead, for example, from municipal distribution water lines or household piping can occur in water regardless of whether the water was first purified at a water treatment plant or otherwise initially at a safe contaminant level. As such, consumer demand for quality potable water has grown in recent years as health awareness concerning contaminants has risen.
In response to these concerns, the water quality enhancement industry has developed a variety of filtration techniques ranging from charcoal filters to reverse osmosis systems. One such common approach to water quality improvement provides for the positioning of a filter at a faucet location where water is drawn for drinking and cooking purposes. The filters used for this application are generally of an in-line variety tapped into the water line upstream from the faucet at the sink. Such filters are quite simple, typically being provided as a retainer holding a filtration medium such as charcoal or the like used to remove contaminants, such as lead, mercury, or carcinogenic compounds from agriculture and industry. These filtration media have a limited capacity to purify generally based on the number of gallons of water passing through them. Following a predetermined flow quantity, the filtration medium must be changed whereupon a next filtering period ensues.
In most instances, a time estimate alone of useful filter medium life is not a dependable method for determining when the filter has reached saturation. The number of gallons used in a household typically varies daily, as well does the quality of water encountered and the type filter used. Consumer attempts at estimating and tracking water consumption in order to determine the filter replacement date are inherently inaccurate. Additionally, filter replacement methods based on a householder's memory of the amount of water used and the projected replacement date are generally not effective.
U.S. Pat. No. 5,050,772 by Brane et al, issued Sep. 24, 1991, entitled "Apparatus for Monitoring a Flow of Fluid Through a Filter Medium" addresses the above consumption tracking problem with the introduction of a monitoring device which is effective for water use monitoring while remaining inexpensive enough for the application at hand. A flow monitoring device is described which may be employed as an in-line fluid flow monitor through filter media of the type typically employed in households upstream of kitchen faucets. In general, the device is structured to include a housing with an input port leading to a rotatable turbine. This turbine is coupled to a reduction gear train positioned within a gear housing. The gear train has a reduction ratio, for example, greater than 1,000,000:1 and provides an eccentric form of output which, in turn, drives a rotatably actuable valve. This valve rotates in increments from a selected starting position and allows the user to hand set the device to monitor a predetermined amount of fluid. As water is passed to a downstream faucet, fluid communication is provided from the turbine chamber through the gear housing and ultimately to and through the valve. Upon monitoring the selected quantity of water, the device automatically cues the user by shutting off the fluid flow exiting an output port leading to the faucet. Thereafter, the user, now reminded to change the filter, may reopen the output port to again allow fluid flow by simply resetting the valve to a selected metering quantity.
The monitor described in U.S. Pat. No. 5,050,772 met with market acceptance for application with filter media requiring replacement after purification from 500 to 1500 gallons of water. Demand developed, however, for a flow monitoring device which could accommodate a much larger flow quantity, for example 2000 gallons. To accommodate this need for enhanced performance, an improved fluid monitor was developed which is described in U.S. Pat. No. 5,065,901 by Brane et al issued on Nov. 19, 1991. This enhanced fluid monitoring device incorporates a gear reduction train with a reduction scheme of greater than 3,900,000:1. As such, fluid monitoring capacity is increased to provide monitoring from 500 to 2400 gallons of water. With the advent of the enhanced monitoring device, filters with larger purifying capacities are usable with a flow monitor which still enjoyed a robust design yet was cost effective and capable of being used under relatively high pressures, as at 400 psi.
In addition to measuring flow, both of these devices are easily adjustable for accommodating various filter capacities and served to cue the user when time for replenishment is at hand. Installation of the monitors remains simple. A common installation is to mount the monitor adjacent to a filtration system on a wall in the sink cabinet. In this regard, the utilization of electronic circuitry, power supplies, or batteries is not needed. As an additional aspect, the devices remain compact in spite of their mechanical monitoring structures which utilize gear reduction ratios exceeding three million to one.
As the popularity of the fluid monitors increases, wider applications for their use is contemplated. For example, small water filtration systems are called for in primitive areas of the world. Often, the water supplies at such locations which are available for filtration will be at unusually low pressures and flow rates. Such local water supplies in third world countries may, for example, be available at 10 psi and at a flow rate of 0.2 gallons per minute. Generally, these pressures and flow rates are insufficient to drive a simple turbine, an aspect that may preclude the use of earlier, inexpensive monitors for that application.
Market demands have further prompted the water quality enhancement industry to supply filter media of increased filtration capabilities. Introduction of these filter media, in turn, have further called for flow monitors with enhanced performance characteristics. Although the above described prior devices have performed admirably, they have not been concerned with safeguarding against over use of the filtration system. Once the predetermined amount of water is consumed, the accompanying saturated filter should be replaced. It has been observed that if the filter is not changed upon reaching its saturation limit, contaminants may loosen and release into the drinking or cooking water supply. In this regard, saturated filters may release more contaminants into the water than would otherwise exist without a filtering device.
Users, unfortunately, have, from time to time, simply reset the monitor instead of changing the filter. In doing so, users may be unexpectedly exposed to potentially higher levels of contamination as particles and bacteria loosen and break free from the filter to the drinking or cooking water. At present, industry and consumers alike would welcome a fluid monitoring system which not only has the advantages of the prior devices but also has a larger capability with an improved safeguard against filter over-use.